File:KAITO Shiritsubomi English Sub Vocaloid シリツボミ

Description
シリツボミ Arrange by シバションP lyrics by 裏花火 セト つるつるP ナタP Music by ナタP You can find the original and the Rin/Len/Miku version oh this page (same lyrics, different arrange) http://shiritsubomi.xxxxxxxx.jp/members.html

Guess what perfectly normal regular human activity is this song about? Len's version has the most hint if you need help.

Romaji here http://wachamaru.livejournal.com/813.html